Fire extinguisher



Patented May 24, 1938 UNITED STATES PATENT OFFICE FIRE EXTINGUISHERApplication January 9, 1936, Serial No. 58,298

Claims.

This invention relates to fire extinguishers of the type wherein thepressure medium is supplied from a cartridge containing, for example,carbon. dioxide in two phases, namely, gas and liquid,

,7, which are released when the cartridge is punctured.

Although fire extinguishers of the general class above mentioned possesscertain inherent advantages, they have heretofore, at least under 10certain conditions of operation, proved objectionable when conditionedfor use because of fluctuating operating pressures due to clogging ofthe cartridge discharge passage by solidification of the pressure mediumtherein incident to a drop in temperature occasioned by the release ofsuch medium and/ or by the formation. of ice under the chilling actionof the pressure medium on fireextinguishing liquid collected in or inthe vicinity of the cartridge discharge passage.

An important object of the present invention is to overcome theabove-mentioned objections, and to that end the invention contemplates agenerally improved structure wherein a free passage at the discharge endof the cartridge is insured from the instant it is punctured until itscontents have been spent, the invention being herein illustrated asembodied in a structure especially adapted for use in fire extinguisherswhich, although normaliy maintained in an upright position, are operatedin an inverted position pursuant to the cartridge puncturing operationfollowing which the contents of the cartridge are released while thecartridge is itself in an inverted position.

Other objects and advantages of the invention 5 will become apparentfrom the following description when taken in connection with theaccompanying drawing, in which-- Fig. l is a fragmental view showing invertical, central section a fire extinguisher embodying the invention,and Fig. 2 is a similar View showing the extinguisher inverted andconditioned for use.

The invention is herein illustrated in connection with an extinguisherof the type which is normally maintained in an upright position, as

shown in Fig. 1, but is adapted to be operated in an inverted position,as shown in Fig. 2, pursuant to its having been conditioned for usewhile inverted. The extinguisher includes a container it which isadapted for the reception of a fire extinguishing liquid, not shown, andfrom which such liquid may be ejected through the usual hose and nozzleunit H. The container is provided at its upper end with a fillingopening 12 and is equipped with the usual screw-threaded neck 14,adapted for the reception of a removable closure IS. The

closure 15 is formed with an upwardly extending barrel-like housing It,within the upper end of which the outwardly flanged end of a springhousing I! is anchored by a clamp nut l8. Carried within the housing H,is a compression sprin in, the lower end of which is supported on theinwardly flanged end of the housing and the upper end of which isadapted to engage the lower end of a sleeve 2 l, slidable within theclamp nut i8 and forming a part of a button-like cap 22 which is securedto a piercer actuating rod 24 and is formed with a flange-like skirt 25,proportioned to accommodate the upper end of the barrel-like housing itas when the piercer actuating rod is moved against the action of itsassociated compression spring. The lower end of the actuating rod 24 isformed with a disc-like head 26, the peripheral margin of which issecured to and 7 forms a liquid and gas-tight connection 'with the lowerend of a sylphon bellows 21, which in turn is secured at its upper endto the outwardly flanged end of the spring housing ll. Connected to thelower end of the actuating rod 24, is a cartridge piercer 28, the shankportion of which is slidable within a central opening 30 formed in thebottom member 3! of a cup-like element 32, the side wall 3 5 of which isprovided at its upper end with an outwardly extending flange 35 which isheld by a gland-like clamp nut 36 in a seated position within ascrew-threaded socket 3'! formed centrally in the closure iii. The shankportion of the cartridge piercer 28 is provided at its lower end with adisc-like stop 38, which normally seats against the bottom member 3i ofthe cup-like element 32.

Fromthe foregoing description, reference being had particularly to themanner in which the bellows 21 is utilized in connection, with thepiercer actuating rod 24 and its associated elements, it will becomeapparent that the structure is such as to provide for reciprocatorymovement of the cartridge piercer from without the container l0 and isalso such as to maintain (in the absence of conventional rod packings,stufiing boxes, gland nuts and the like) a perfect seal between thepiercer actuating rod and the closure I5 through which such rod extends.

Depending from the clamp nut 36, is a cylindrical baffie 49' which isprovided at its upper end with a plurality of apertures 41 and is formedat its lower end with an internally screw-threaded sleeve-like socket 42adapted for the reception of the upper screw-threaded end of a cartridgeclosure C, which includes a screw plug 43, the lower end of which issecured within the neck or throat of a cartridge 44, within which issealed a pressure-generating medium such as compressed carbon dioxide.The cartridge closure C also includes a centrally disposed wire-liketube 45, the passage, not shown, of which functions as a meteringaperture for the cartridge which is normally maintained closed by adiaphragm-like seal 46, adapted to be held in seated position by agland-like clamp nut 41, having an exit aperture 48, disposed inalignment with the tube 45 and adapted to permit the piercing end of thecartridge piercer to move into seal-puncturing position, as illustratedin Fig. 2.

From the foregoing description, reference being had particularly to thebaffle 40 in association with the cartridge closure C, it will beunderstood that such baffle and such closure collectively serve as abell or air trap, when the extinguisher is inverted, within which liquidentering the bell is permitted to rise to only a limited extent due tothe counter pressure which is exerted on the rising liquid by thetrapped air above the liquid level within the bell, it being observedthat a state of equilibrium as between the liquid pressure and thepressure exerted by the entrapped air is effected incident to arelatively slight rise of liquid within the bell, with the resuit thatthe liquid level is maintained at a very substantial distance below andwell out of contact with the cartridge closure and hence at asubstantial distance from the vicinity of its preformed apertures aswell as the aperture which is formed in the cartridge seal incident tothe puncturing operation.

Although the bell structure or air trap, hereinbefore described asincluding the baffle 40 and the cartridge closure C, serves to maintainthe liquid contents of the container 0 well out of the vicinityof theapertures of the cartridge closure when the extinguisher is inverted, afurther precaution is taken for a somewhat analogous purpose, namely, toprevent liquid from finding its way through the apertures 4| and thenceinto the vicinity of the exit aperture of the cartridge closure when theextinguisher is subjected to jolts and jostling while in an uprightposition; and to that end there is provided an anti-slosh baflle 50, inthe form of a cylindrical skirt, which is secured at its upper end tothe peripheral margin of the clamp nut 36. The baffle 50 is of a lengthsubstantially equal to the baflle 40 and extends downwardly thereaboutso as to form a relatively narrow annular passage 5|, access to whichfrom the container I0 is afforded at its lower end and therefore at asubstantial distance from the apertures 4|. The remoteness of theapertures 4| to the point of communication afforded between the annularpassage 5| and the container l0, coupled with the fact that the annularpassage is relatively narrow, obviously account for the effectivenesswith which the bafile structure just described is adapted to function inpreventing liquid from finding its way from the container l0 into thebell chamber when the liquid content of the extinguisher is undulydisturbed as by jostling while the extinguisher is in its uprightposition.

Although the baflle structure, hereinbefore described as including thebaffles 40 and 50, serves under all conditions to effectively preventfireextinguishing liquid from collecting at or in the vicinity of theexit aperture 48 and hence eliminates the possibility of ice beingformed by the chilling effect of the pressure medium as it is releasedfrom the cartridge, such structure in itself does not preventsolidification of the liquid content of the cartridge at or in thevicinity of the apertures of the cartridge closure C when it is releasedfrom the inverted cartridge. Solidification of the pressure medium isprevented, however, by the aid of a simple metering expedient which isadapted to permit the release of never more than a definite fractionalportion of the liquid content and is herein illustrated as a tube 52,one end of which is secured in the cartridge closure C in alignment withthe tube 45 thereof and the other end of which is provided with a collar54, carrying a screen 55, which overlies and serves to guard the tubepassage against the entrance of such foreign particles as may be presentin the cartridge. When considering the function of the screen 55, it isto be noted that any foreign particles that may find their way throughthe mesh of such screen will be entrapped in the space afforded betweenthe tube 45 and lower wall-portion of the tube 52, into which lattertube the tube 45 projects a short distance,

In order that a clear understanding as to the required length of themetering tube 52 may be had, it may be well to point out that thedrawing illustrates that tube in a proper relation to the depth of theliquid carbon dioxide content (at 40 F.) of a cartridge 44 which hasbeen employed with excellent results in connection with a so-called 2gallon extinguisher carrying that quantity of suitable fireextinguishing medium, for example, an anti-freeze solution such as asolution of calcium chloride in water of sufficient concentration todepress the freezing point to 40 F. The cartridge 44 herein illustratedhas a volumetric capacity of approximately 203 c. c. and containsapproxim tely 65 c. c. (which is approximately 2.5 oz. avoirdupois) ofliquid carbon dioxide at -40 F. Thus it will be obvious that the liquidcarbon dioxide is equal by volume to approximately one-third thevolumetric capacity of the cartridge and is also equal to appr xima elyone-half the vq um o the ca b dioxide gas content of the cartridge. Itis to be further observed, particular reference being had to Fig. 2 thatthe tube 52 terminates at such a point with relation to the level of theliquid carbon dioxide (at 40 F.) that approximately onequarter of theliquid content of the cartridge may be expelled before the inlet end ofthat tube is uncovered or exposed.

Taking into account the foregoing discussion of the relation of thefactors peculiar to the example herein given as a practicable embodimentof the invention, it is obvious that one skilled in the art may readilyadapt it to any size of fire extinguisher. To illustrate, let it beassumed that the invention is to be adapted for use in connection with a5-gallon extinguisher. In that event an appropriate cartridge to beemployed would have a volumetric capacity of approximately 406 c. c. andwould contain approximately c. c. of liquid carbon dioxide at .40 F.,whereas the length of the metering tube would be such with respect tothe depth of the liquid carbon dioxide (at 40 F.) that approximatelyone-quarter of the liquid content of the cartridge would be expelledbefore the inlet end of that tube is uncovered or exposed.

A peculiarity, concerning the operation of the device embodying thepresent invention, resides in the fact that, under temperatureconditions of 40 F., the approximate one-quarter of the liq uid carbondioxide content, which is expelled in liquid phase immediately followingthe inversion and puncturing of the cartridge, is insufficient to lowerthe temperature within the metering tube or any of its communicatingpassages to a surficient extent to form solid carbon dioxide. Thispeculiarity is attributed to the fact that even though the temperatureof the fire extinguishing medium, within which the cartridge and itsvarious associated elements are submerged, is at an operatingtemperature of 40 it is nevertheless sufiiciently warm to furnish ampleheat to the liquid carbon dioxide as it is released to prevent thatliquid from reaching the extremely low temperature of F. which isrequired to transform it into a solid.

Another peculiarity, concerning the operation of the device embodyingthe present invention, resides in the fact that the liquid carbondioxide content, which is expelled in liquid phase, is sufficient inamount to not only quickly satisfy the needs of the fire extinguishingmedium from a carbon dioxide absorption standpoint, but also is enoughin excess of the amount required to satisfy the absorption needs of thefire extinguishing medium to quickly generate a desired initialoperating pressure in the container.

Following the discharge of the liquid carbon dioxide in liquid phase,the operating pressure, which is initiated by reason of the fact that aportion of such liquid is transformed into a gas, is maintainedsuflicient, by egress of the original gas content of the cartridge andby the egress of the gas into which the remaining liquid content istransformed, to insure an excellent discharge pressure until the entirequantity of the fire extinguishing medium is expelled.

Regarding the volumetric ratio of liquid content and gas content in thesealed cartridge, which in the example given is in the order ofapproximately 1 to 2 under operating conditions of --40 F., it will beunderstood that the cartridge may be charged under such conditions aswill insure that ratio at that temperature. In other words, if thevolumetric capacity of a cartridge is known, it may be charged with agas such as carbon dioxide gas, the critical temperature of which isknown, under such temperature and pressure conditions as willpredetermine the approximate volumetric ratio of the liquid content andgas content in the sealed cartridge at any temperature below thecritical temperature of the gas employed,

Although the operation of the device embodying the present invention hasbeen described under operating conditions of 40 F., at which time thecartridge is approximately one-third full of liquid carbon dioxide,approximately one-quarter of which is expelled in liquid phase, it willbe understood that that particular temperature has been selected in thediscussion of the operation because that is customarily considered to bethe minimum temperature at which extinguishers of the present type arerequired to successfully operate. The present invention obviously makespossible successful operation at higher and at lower temperatures thanthe particular temperature mentioned, namely, -40 F.

Concerning the operation of the device at temperatures higher than 40F., it is to be borne in mind that as the operating temperatures isincreased above -40 F. the absorption demands of the fire extinguishingliquid are decreased, with the result that less carbon dioxide isrequired to satisfy the needs of the fire extinguishing medium from anabsorption standpoint. It has been determined, by experiment, that asthe operating temperature is increased above -40 F. the requiredoperating pressure is established in correspondingly shorter periods oftime, and that once the operating pressure is established it ismaintained ample throughout the discharge period of the extinguisher.

In adapting the invention for use at operating temperatures lower than40 F., it is to be borne in mind that the lower the operatingtemperature encountered the greater the absorption factor of a givenfire extinguishing medium, and with this in mind the problem may, ofcourse, be sat isfactorily met, in view of the facts herein set forth,by providing for the initial discharge of a sufficient quantity of thepressure medium, while in liquid phase and without encountering theformation of solid carbon dioxide, to quickly satisfy the needs of thefire extinguishing medium from an absorption standpoint, and byproviding for the release thereafter of a sufficient quantity of thepressure medium in the form of a gas to maintain the operating presstueat a satisfactory value throughout the discharge period of theextinguisher.

Although the invention is illustrated in connection with an extinguisherof the invertible type wherein the contents of the cartridge arereleased in part as a liquid and in part as a gas, it may be employedwith extinguishers of the non-invertible type which are adapted tooperate while in an upright position, in which case the entire contentsof the cartridge may be released in the form of a gas.

In the case of the invertible type of extinguisher, it becomes necessaryto guard against solidification of the liquid at its point of releasefrom the cartridge and to also there guard against the formation of icedue to the presence of moisture and the chilling action of the pressuremedium at its point of release from the cartridge. Whereas, in the caseof the non-invertible type of extinguisher it becomes necessary to guardonly against the formation of ice, inasmuch as solidification of thecartridge content cannot take place when it is released in the form of agas. The present invention is equally adapted for use in both of theseinstances, because it so functions that it not only obviatessolidification of the carbon dioxide when it is released in the form ofa liquid, but also prevents the formation of ice by excluding the fireextinguishing liquid from the vicinity of the exit aperture where thecarbon dioxide is released in the form of either gas or liquid.

No claim is made herein to the cartridgepuncturing unit per se whichincludes the bellows 21 and its several cooperatively associated parts,such unit being the subject-matter of a copending application for Fireextinguishers, Serial No. 137,953, flied April 20, 1937, in the name ofFred Albert Dodelin.

Although only one form of the invention is herein shown and described,it will be understood that various changes may be made without departingfrom the spirit of the invention or the a scope 9f the following claims.

What is claimed is:

1. For use in a fire extinguisher employing a liquid fire-extinguishingmedium, a sealed cartridge containing a pressure medium to be released,protective means associated with the exit end of the cartridge to bepunctured for excluding liquid fire-extinguishing medium from the exitend of the cartridge and for thus obviating the formation there of iceunder the chilling action of pressure medium pursuant to the puncturingoperation, said protective means including a tube-like baille connectedat one end to and forming with the exit end of the cartridge a chamberadapted to communicate with the cartridge when such cartridge ispunctured, said baffle being provided with an aperture remotely locatedwith respect to the exit end of said cartridge and adapted to serve as acommunicating passage between the interior and exterior of said chamber.

2. For use in a fire extinguisher employing a liquid fire-extinguishingmedium, a sealed cartridge containing a pressure medium to be released,protective means associated with the exit end of the cartridge to bepunctured for excluding liquid fire-extinguishing medium from the exitend of the cartridge and for thus obviating the formation there of iceunder the chilling action of pressure medium pursuant to the puncturingoperation, said protective means including a tube-like bafile connectedat one end to and forming with the exit end of the cartridge a chamberadapted to communicate with the cartridge when such cartridge ispunctured, said baffie being provided with an aperture remotely locatedwith respect to the exit end of said cartridge and adapted to serve as acommunicating passage between the interior and exterior of said chamber,an anti-slosh baffle disposed in an embracing relation to thefirst-mentioned bafile and forming therewith a passage open at one endand communicating at its other end with said chamber by way of saidaperture.

3. For use in a fire extinguisher employing a liquid fire-extinguishingmedium, a sealed cartridge containing a pressure medium to be re leased,protective means associated with the exit end of the cartridge to bepunctured for excluding liquid fire-extinguishing medium from the exitend of the cartridge and for thus obviatlng the formation there of iceunder the chilling action of pressure medium pursuant to the puncturingoperation, said protective means including a tube-like baflle connectedat one end to and forming with the exit end of the cartridge a chamberadapted to communicate with the cartridge when such cartridge ispunctured, said bafile being provided with an aperture remotely locatedwith respect to the exit end of said cartridge and adapted to serve as acommunicating passage between the interior and exterior of said chamber,an anti-slash bafiie disposed in an embracing relation to thefirst-mentioned baffie and forming therewith a passage open at one endand communicating at its other end with said chamber by way of saidaperture, said bailies being adapted to collectively serve in a fireextinguisher as an anti-slosh device when such extinguisher is in anupright position and the first-mentioned bailie being adapted to serveas a bell-type air trap when such extinguisher is in an invertedposition to limit the rise of fire extinguishing liquid therein to alevel well below the vicinity of the exit end of the cartridge.

4. In a fire extinguisher of the cartridge type, a container for a fireextinguishing liquid, a sealed cartridge containing a pressure mediumwhich is to be released and which at 40 F. is in both gas and liquidphases, the pressure medium being in such amount that the volumetricratio of the liquid content and gas content in the sealed cartridge isapproximately in the order to l to 2 at -40 F., metering means renderedeffective upon puncturing the cartridge under temperature conditions of40 F. to insure release of approximately one-quarter of said liquidcontent while in liquid phase and to insure release of the remainingpressure medium in the form of a gas.

5. In a fire extinguisher of the cartridge type, a container for a fireextinguishing liquid, a sealed cartridge containing a pressure mediumwhich is to be released and which at 40 F. is in both gas and liquidphases, the pressure medium being in such amount that the volumetricratio of the liquid content and gas content in the sealed cartridge isapproximately in the order of 1 to 2 at 40 F., metering means renderedeffective upon puncturing the cartridge under temperature conditions ofl0 F. to insure release of approximately one-quarter of said liquidcontent while in liquid phase and to insure release of the remainingpressiu'e medium in the form of a gas, said metering means including ametering tube the inlet end of which under temperature conditions of -40F. is located at such a distance below the level of said liquid thatapproximately one-quarter of said liquid content is above the level ofsaid inlet end.

6. In a fire extinguisher of the cartridge type, a container for a fireextinguishing liquid, a sealed cartridge containing a pressure mediumwhich is to be released and which at 40 F. is in both gas and liquidphases, the pressure medium being in such amount that the volumetricratio of the liquid content and gas content in the sealed cartridge isapproximately in the order of 1 to 2 at 40 F., metering means renderedeffective upon puncturing the cartridge under temperature conditions of40 F. to insure release of approximately one-quarter of said liquidcontent while in liquid phase and to insure release of the remainingpressure medium in the form of a gas, the volumetric capacity of saidcontainer and of said cartridge being approximately in the order of 9470. c. (2 gallons) and 203 c. c.

7. In a fire extinguisher of the cartridge type, a container for a fireextinguishing liquid, a sealed cartridge containing a pressure mediumwhich is to be released and which at 40 F. is in both gas and liquidphases, the pressure iedium being in such amount that the volumetricratio of the liquid content and gas content in the sealed cartridge isapproximately in the order i of l to 2 at 40 F., metering means renderedefiective upon puncturing the cartridge under temperature conditions of-40 F. to insure release of approximately one-quarter of said liquidcontent while in liquid phase and to insure release of the remainingpressure medium in the form of a gas, said metering means including ametering tube the inlet end of which under temperature conditions of 40F. is located at such a distance below the level of said liquid thatapproximately one-quarter of said liquid content is above the level ofsaid inlet end, the volumetric capacity of said container and of saidcartridge being approximately in the order of 947 c. c. (2 gallons) and203 c. c.

8. In a fire extinguisher of the cartridge type, a container for a fireextinguishing liquid, a sealed cartridge containing a pressure mediumwhich is to be released and which is in such amount that at a giventemperature below its critical temperature the volumetric ratio of theliquid content to the volumetric capacity of the sealed cartridge isdefinite, metering means rendered eifective upon puncturing thecartridge to relewe the contents thereof, said metering means includinga metering tube having an inlet end which (when an operating conditionof --40 F. is encountered) is at a distance below the level of theliquid content corresponding to the approximate fractional portion ofthe liquid content then required tosatisfy the needs (from an absorptionstandpoint) of the fire extinguishing liquid.

9. In a fire extinguisher of the cartridge type, a container for a fireextinguishing liquid, a sealed cartridge containing a pressure mediumwhich is to be released and which is in such amount that at a giventemperature below its critical temperature the volumetric ratio of theliquid content to the volumetric capacity of the sealed cartridge isdefinite, metering means rendered efiective upon puncturing thecartridge to release the contents thereof, said metering means includinga metering tube having an inlet end which (when the operatingtemperature encountered is such that the inlet end of the tube issubmerged) is at a distance below the level of the liquid contentcorresponding to the approximate fractional portion of the liquidcontent then required to satisfy the needs (from an absorptionstandpoint) of the fire extinguishing liquid.

10. For use in a fire extinguisher, a sealed cartridge containing apressure medium which at relatively low temperatures with respect to thecritical temperature thereof is at least in part in liquid phase, and ametering tube extending into said cartridge to such an extent that itsinlet end is below the level of the liquid at such relatively lowtemperatures, whereby upon puncturing the cartridge at such temperaturesa portion of the liquid is released in liquid phase and thereafter theremainder of the pressure is released in the form of a gas.

GEORGE ENNIS FERGUSON.

' CERTIFICATE OF CORRECTION.

Patent No., 2,118,597, May EA, 1958.

GEORGE ENNIS FERGUSON.

It:ishereby certified that error appears in the printed specificationoftheabovernmmeredpatentrequiringcorrectionasfellows: Page2,secondColumn, line3,strike out the word "definite"; page5, first column, line69, for "temperatures" read temperature; and.that the said LettersPatent should be read with these eorrectionsthereinthatthesamemsyconformto the record of the case in the Patent Office.

Signed and sealed this 5th day of Jul A. D. 19 8.

Henry Van Arsdale, 7 Acting Commissioner of Patents.

